Flowise - Weak Default JWT Secrets in Authentication Middleware

published 2026-04-16 6 mo ago modified 2026-10-25 14 d ago also GHSA-cc4f-hjpj-g9p8 , EUVD-2026-43228

cvss: 9.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.7%; EPSS 0.7% chance of exploitation in 30 days, percentile 51%
public exploits: 0; none known

Flowise before 3.1.0 (affected versions 3.0.13 and earlier) uses weak hardcoded default JWT secrets ('auth_token', 'refresh_token') and default audience and issuer values ('AUDIENCE', 'ISSUER') in the enterprise passport authentication middleware (packages/server/src/enterprise/middleware/passport/index.ts). When the corresponding environment variables (JWT_AUTH_TOKEN_SECRET, JWT_REFRESH_TOKEN_SECRET, JWT_AUDIENCE, JWT_ISSUER) are not set, the application silently falls back to these publicly known defaults, allowing an attacker to forge valid JWTs and impersonate any user, including administrators, resulting in authentication bypass.

Patch / fix

fixed in 2

npm flowise 3.1.0
Flowise Flowise 3.1.0

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: total
Assessed: 3 mo ago (2026-07-13)

Exploit prediction

0.66% chance of exploitation in the next 30 days, higher than 51% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	9.3	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CNA	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA	4.0	9.3	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
GitHub	3.1	5.6	CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N

Affected packages

ecosystem	package	affected	fixed in
npm	flowise	<3.1.0	3.1.0

Affected products

Flowise Flowise

Classification

Weakness

CWE-321 Use of Hard-coded Cryptographic Key
CWE-327 Use of a Broken or Risky Cryptographic Algorithm

References

github.com /FlowiseAI/Flowise/security/advisories/GHSA-cc4f-hjpj-g9p8
vendor-advisory, web
vulncheck.com /advisories/flowise-weak-default-jwt-secrets-in-authentication-middleware
third-party-advisory
github.com /FlowiseAI/Flowise
package

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary